/*
 * Copyright 2008-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.broadleafcommerce.common.extensibility.context;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

import org.springframework.beans.BeansException;
import org.springframework.beans.FatalBeanException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractXmlApplicationContext;
import org.springframework.core.io.Resource;

/**
 * Standalone XML application context, taking the locations of one or more
 * source applicationContext xml files and one or more patch xml files.
 * 
 * <p>One or more source files merge together in pure override mode. Source
 * files are merged in the order specified. If a bean id is repeated in a subsequent
 * source file, the subsequent bean definition will always win. This is the same behavior
 * as Spring's default mechanism for merging 1 to N applicationContext files.</p>
 * 
 * <p>Each patch file is merged with the combined source, one patch file at a time. This
 * merge is performed in true merge mode. Therefore, if a bean id is delivered in a patch
 * file with the same id as a bean in the source, the patch will merge with the source. This
 * could result in an override of the class definition for the bean, or additional or changed
 * property elements within the bean definition.</p>
 * 
 * @author jfischer
 *
 */
public class MergeFileSystemAndClassPathXMLApplicationContext extends AbstractXmlApplicationContext {

	protected Resource[] configResources;

	protected Resource[] getConfigResources() {
		return this.configResources;
	}

	public MergeFileSystemAndClassPathXMLApplicationContext(String[] classPathLocations, String[] fileSystemLocations) throws BeansException {
		this(classPathLocations, fileSystemLocations, null);
	}

	public MergeFileSystemAndClassPathXMLApplicationContext(String[] classPathLocations, String[] fileSystemLocations, ApplicationContext parent) throws BeansException {
		super(parent);
		
		ResourceInputStream[] classPathSources;
		ResourceInputStream[] fileSystemSources;
		try {
            classPathSources = new ResourceInputStream[classPathLocations.length];
            for (int j=0;j<classPathLocations.length;j++){
                classPathSources[j] = new ResourceInputStream(MergeClassPathXMLApplicationContext.class.getClassLoader().getResourceAsStream(classPathLocations[j]), classPathLocations[j]);
            }
			
			fileSystemSources = new ResourceInputStream[fileSystemLocations.length];
			for (int j=0;j<fileSystemSources.length;j++){
				File temp = new File(fileSystemLocations[j]);
                fileSystemSources[j] = new ResourceInputStream(new BufferedInputStream(new FileInputStream(temp)), fileSystemLocations[j]);
			}
		} catch (FileNotFoundException e) {
			throw new FatalBeanException("Unable to merge context files", e);
		}
		
		this.configResources = new MergeApplicationContextXmlConfigResource().getConfigResources(classPathSources, fileSystemSources);
		refresh();
	}

}
